Vacancies and lease rates at US shopping centers continued to worsen in the second quarter, but the slowing pace of the deterioration hints at a recovery starting in the coming quarters. Vacancies at large malls in the top 80 US markets rose to 9% in the second quarter, up from 8.9% during the first quarter, according to real-estate research company Reis. Mall vacancies have increased steadily for nearly four years as consumers reined in their spending and retailers closed stores and curtailed expansions.